This application claims the benefit of priority under 35 U.S.C. xc2xa7 119 of German Patent Application No. 101 03 125.4 filed on Jan. 24, 2001.
The invention relates to an optical fiber coupling unit for coupling an optical fiber to an optical waveguide component, in particular to a planar optical waveguide component, such as an optical chip for example. The invention also relates to an optical waveguide arrangement and a method of producing an optical fiber coupling unit.
For coupling optical fibers, for example glass fibers, to an optical chip, on which optical structures are provided, today the optical fibers are usually bonded onto the chip by means of an adhesive. When doing so, the optical fibers are generally bonded with their front-end faces onto an associated end face of the chip.
A typical optical fiber contains a fiber core and a fiber cladding surrounding the fiber core, which together form the actual light guide. To protect the optical fiber, it, i.e. the arrangement comprising the fiber core and fiber cladding, is usually provided with a sheathing, for example in the form of a coating applied directly to the fiber cladding. The coating typically consists of plastic. The sheathing may, furthermore, have an additional outer layer, for example the coating may be additionally buffered with a resistant flexible material, as also used for cables.
The outside diameter of a standard single-mode glass fiber with a fiber core and fiber cladding, that is without the sheathing, is typically 125 xcexcm. The resulting end face of the individual optical fiber is not sufficient in this case to achieve a stable and reliable adhesive bond between the end face of the optical fiber and the chip.
In the case of a known coupling unit for coupling one or more optical fibers, what is known as a fiber array is adhesively bonded onto the optical chip to achieve a stable and reliable bond.
FIG. 1 shows such a fiber array 101 according to the prior art in a view from the front. The fiber array 101 is made up of a base plate 103, a V-groove platelet 104, in which a plurality of V grooves 105 arranged at a distance from one another and running parallel to one another have been formed, and a plurality of optical fibers 106, which have been laid in the associated V grooves 105. In this case, generally the optical fibers 106 are first laid in the V grooves 105. Then, the V-groove platelet 104 together with the optical fibers 106 and the base plate 103 are bonded together, whereby the optical fibers 106 are fixed in the V grooves 105. The end face 107 of the arrangement comprising the V-groove platelet 104 together with the optical fibers 106 and base plate 103 is subsequently ground and polished, so that a planar coupling face is created for bonding the fiber array 101 onto a chip. As can be seen from FIG. 2, the fiber array 101 is attached by this coupling face to the associated extreme end of an optical chip 108 to establish an optical coupling.
To ensure a precise and controlled coupling of the optical fibers 106 onto the chip 108, the V-groove platelet 104 must be fabricated very accurately. The fabrication of V-groove platelets with sufficiently high precision is achieved for example by etching. However, because of the small dimensions of the V grooves 105, this fabrication is complex.
The invention provides an optical fiber coupling unit for a optical fiber, by means of which coupling unit the optical fiber can be optically coupled to an optical waveguide component in a reliable way, and which has a simple construction and can consequently be realized at low cost. The invention also provides a method of producing an optical fiber coupling unit, with which the optical fiber coupling unit according to the invention can be precisely produced in a simple way.